Isaac, you and your wife have three kids ... "So we can stop having children," Zac Hanson, 38, jokes. "Is that your form of birth control?" Haines asks. "It's old school. Distance, it works!" ...

Hanson's new album, 'Red Green Blue,' is out now. Plus, an ET exclusive performance of their new track, 'Write You a Song.' Isaac, Taylor and Zac have 15 children between them. Hanson opens up ...